Fluid transfer systems may comprise a plurality of pipes designed for flow of fluid therein.
The plurality of pipes may be designed with a first, inner fluid channel, surrounded by a second, outer fluid channel. The inner fluid channel and the outer fluid channel may be generally coaxially aligned therebetween. A fluid may flow within the inner fluid channel and the outer fluid channel.
In some systems the plurality of pipes may comprise a first pipe configured to rotate about a second pipe.